Crossing arm assembly

Abstract

A school bus is equipped with a crossing arm mechanism that is mounted on the front bumper at the passenger side. The mechanism includes a crossing arm assembly that is pivoted between a retracted (stored) position adjacent the front bumper and an extended (operative) position where the crossing arm assembly extends outwardly of the bus bumper in a perpendicular fashion to control pedestrian traffic. The crossing arm assembly includes a plastic bracket that is pivotally attached to an actuating mechanism and a cantilever beam that is attached to the bracket at one end. The bracket has two vertically spaced pivot arms and a beam mounting portion that supports the cantilever beam. The cantilever beam is a plastic extrusion that comprises upper and lower tubular sections that are interconnected by a web portion. The extrusion is modified at one end for attachment to the bracket.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A crossing arm assembly of plastic construction for pivotal attachment to the front end of a school bus for blocking pedestrian traffic from crossing immediately in front of the school bus when the school bus is stopped comprising; a bracket that is adapted for pivotal attachment to a support and an elongated cantilever beam that is attached to the bracket at one end of the beam;   the bracket having two molded plastic parts that are secured together to form two vertically spaced pivot arms and a beam mounting portion;   the beam mounting portion including a lower hollow, triangular support gusset that has a narrow horizontal blade at the top, a lower hollow horizontal rectangular tube connected to the horizontal blade, an upper hollow horizontal rectangular tube and a short vertical blade disposed between and connected to inboard ends of the rectangular tubes;   the elongated cantilever beam being in the form of a plastic extrusion that comprises upper and lower stiff box sections that are interconnected by a flexible web portion,   the lower box section having a slit in a lower wall receiving the horizontal blade and a short slit in an upper wall receiving the vertical blade;   the upper box section having a short slit in a lower wall receiving the vertical blade;   an inboard end of the web portion being spaced from inboard ends of the box sections to accommodate the vertical blade, and   the elongated cantilever beam being secured to the bracket by the tubes being disposed in the box sections and fastened to the back walls of the box sections.   
     
     
       2. The crossing arm assembly as defined in claim 1 further wherein the pivot arms are hollow and the crossing arm assembly further comprises an elbow that is held in each arm and that includes a respective pivot pin that is disposed outwardly of the pivot arm. 
     
     
       3. The crossing arm assembly as defined in claim 1 wherein the web has a smooth front face between the box sections and the crossing arm assembly further comprises a visible tape that is adhered to the front face of the flexible web. 
     
     
       4. A crossing arm assembly of plastic construction for pivotal attachment to the front end of a school bus for blocking pedestrian traffic from crossing immediately in front of the school bus when the school bus is stopped comprising; a bracket that is adapted for pivotal attachment to a support and an elongated cantilever beam that is attached to the bracket at one end of the beam;   the bracket having two molded plastic parts that arc secured together to form two vertically spaced pivot arms and a beam mounting portion;   the beam mounting portion including a lower hollow support gusset, a lower tube supported by the gusset and an upper tube spaced from the lower tube in the vertical direction;   the elongated cantilever beam being of unitary plastic construction including vertically spaced tubular sections of closed geometric cross section that are interconnected by a flexible web, and   the tubes of the bracket being disposed in the tubular sections and fastened to the tubular sections to secure the cantilever beam to the bracket.   
     
     
       5. The crossing arm assembly as defined in claim 4 wherein the tubular sections have a cross section that is polygonal. 
     
     
       6. The crossing arm assembly as defined in claim 4 wherein the tubular sections have a cross section that is round. 
     
     
       7. The crossing arm assembly as defined in claim 4 wherein the tubes of the bracket and the tubular sections of the cantilever beam have cross sections that are of a similar closed geometric shape. 
     
     
       8. An elongated, sag resistant, plastic beam for a crossing arm assembly adapted for pivotal attachment to the front end of a school bus for blocking pedestrian traffic from crossing immediately in front of the school bus when the school bus is stopped, the plastic beam comprising; upper and lower tubular sections of closed geometric cross section that are vertically spaced from each other,   an integral web interconnecting the tubular sections that is laterally flexible so that the tubular sections can move relative to each other in the lateral direction, and the upper and lower tubular sections and the flexible web being modified at one end of the beam for attachment to a support in cantilever fashion, the lower tubular section having a lower side with a slit for receiving a beam mounting portion.   
     
     
       9. The elongated plastic beam as defined in claim 8 wherein the plastic beam is an extrusion that is modified at the one end. 
     
     
       10. The elongated plastic beam as defined in claim 8 wherein the upper and lower tubular sections have thin walls and polygonal cross sections. 
     
     
       11. The elongated plastic beam as defined in claim 8 wherein the upper and lower tubular sections have thin walls and round cross sections. 
     
     
       12. The elongated plastic beam as defined in claim 8 wherein the flexible web has a smooth front face and wherein a tape is adhered to the smooth front face to improve visibility. 
     
     
       13. An elongated, sag resistant, plastic beam of one piece construction for a crossing arm assembly adapted for pivotal attachment to the front end of a school bus for blocking pedestrian traffic from crossing immediately in front of the school bus when the school bus is stopped, the plastic beam comprising; upper and lower tubular sections of closed geometric cross section that are vertically spaced from each other,   the upper and lower tubular sections having a minimum length of approximately five feet,   a thin stiff integral web interconnecting the tubular sections substantially along the entire length thereof,   the web being laterally flexible so that the tubular sections can move relative to each other in the lateral direction, and   the upper and lower tubular sections and the flexible web being modified at one end of the beam for attachment to a support in cantilever fashion, the lower tubular section having a lower side with a slit for receiving a beam mounting portion.   
     
     
       14. The elongated plastic beam as defined in claim 13 wherein the plastic beam is an extrusion that is modified at the one end. 
     
     
       15. The elongated plastic beam as defined in claim 13 wherein the web has a thickness of approximately 0.075 inches. 
     
     
       16. The elongated plastic beam as defined in claim 15 wherein the upper and lower tubular sections have thin walls that are approximately 0.050 inches in thickness. 
     
     
       17. The elongated plastic beam as defined in claim 13 wherein the flexible web has a smooth front face and wherein a tape is adhered to the smooth front face to improve visibility.